Tribology of enhanced turning using biolubricants: A comparative assessment

The tribological behavior of cutting is a decisive factor in changing the production cycle, cost, and quality of parts. Minimum quantity lubrication (MQL) based on environmentally friendly biolubricants can convert contact conditions in cutting zones, but it cannot meet the manufacturing requirements of difficult-to-machine materials in the continuous friction turning process. Under the boundary conditions of high temperature, high cutting speed, and high pressure at the tool-workpiece interface, the scientific issue of performance enhancement remains unclear and thus has been the focus of academic and industry research. Moreover, under the continuous cutting boundary condition, technology enhancement as a development trend has not yet been systematically reviewed. Wetting, friction reduction, and heat transfer mechanisms have also not yet been investigated. In this study, the cooling lubrication mechanism and technical iteration motivation of MQL were initially analyzed. Subsequently, a quantized comparative assessment of cutting force, cutting temperature, tool wear, and surface quality under enhanced environmentally friendly lubrication turning, including parts enhanced by nanoparticles, cryogenic medium, ultrasonic vibration, and textured tools, was performed. The technical performance, parameter optimization, and mechanism of enhanced MQL were comprehensively studied, and the development stages of biolubricant MQL turning (MQLT) were fully reviewed. Finally, the development trend of the theory and application of MQLT for difficult-to-machine materials was prospected. This study may be used by scientists to deeply understand the mechanism, tribological behavior, and development trend of lubrication in relation to continuous cutting.